TECHNICAL FIELD OF INVENTION
[0001] The present invention relates to a scanning type probe microscope, and particularly
to a scanning type probe microscope in which a deflection amount of a cantilever is
detected by an optical lever method and a probe finely moves vertically to control
a distance between the probe and a sample.
BACKGROUND ART
[0002] A scanning type probe microscope is a device that brings a probe with a sharp fore-end
closer to a sample to measure a force produced between the probe and the sample, by
which a shape of a sample surface and the like are measured at an atomic level.
[0003] The scanning type prove microscope includes a so-called cantilever with a very small
spring constant. The cantilever has a probe at a fore-end thereof. A fore-end of the
probe is extremely sharp in the nm order. A deflection amount of the cantilever by
atomic force acting between the probe and the sample surface is measured, while horizontally
moving the sample or the probe for scanning.
A base portion of the cantilever is fixed to a cantilever holding portion.
[0004] As operation modes of the scanning type probe microscope, a contact mode and a dynamic
mode are known.
In the contact mode, a fine vertical movement amount z of the sample is adjusted so
as to make the force between the sample and the probe constant in the scanning. Accordingly,
during the scanning, a deflection amount θ of the cantilever is constant. The sample
surface shape can be known from output of the fine vertical movement amount z of the
sample when the deflection amount θ of the cantilever is adjusted to be constant.
[0005] In the dynamic mode, the sample surface is scanned while constantly vibrating the
probe. When the probe approaches the sample at an atomic level, an amplitude and a
resonance frequency of the vibration of the probe are affected by attracting force
or repulsive force by the sample, thereby being changed. Consequently, the fine vertical
movement amount z of the sample is adjusted so as to make the amplitude or the resonance
frequency of the probe constant. The sample surface shape can be known from the output
of the fine vertical movement amount z of the sample.
[0006] As means for measuring the deflection amount θ of the cantilever, a detection optical
system by a method generally called optical lever method is used. In FIG. 4(a), one
example of a detection optical system 40 by the conventional optical lever method
is shown. A laser light source 43 and light detection means 44 are arranged in a plane
including a long axis of a cantilever 42 above the cantilever 42 attached to a fore-end
of a cantilever holding portion 41. The light detection means 44 is, for example,
a quadrant photodiode.
[0007] Incident light 45 emitted from the laser light source 43 is reflected on an upper
surface of the cantilever 42, so that reflected light 45a enters the light detection
means 44. The light detection means 44 (the quadrant photodiode) has four light-receiving
regions 44a. When the deflection amount θ of the cantilever 42 has a reference value,
the reflected light 45a enters a center of the four light-receiving regions 44a.
[0008] As shown in FIG. 4(b), when deflection occurs in the cantilever 42, thereby changing
as shown by a cantilever 42a indicated by dashed lines, the reflected light 45a moves
from the center of the light detection means 44 as shown by reflected light 45b indicated
by a dashed line. The four light-receiving regions 44a output voltages in accordance
with received light intensity. Thus, when the reflected light 45a moves, differences
are caused in the output voltage of the respective light-receiving regions 44a. From
the caused differences in the output voltage, a movement amount of the reflected light
45b can be known, from which the deflection amount θ of the cantilever 42 can be known.
[0009] A detection sensitivity S in the detection optical system 40 by the optical lever
method is given by S=D/d=2L/K, where a displacement of the reflected light 45b on
the light detection means 44 is D, a length of the cantilever 42 is K, a light path
length of the reflected light 45b is L, and a deflection displacement of the fore-end
of the cantilever 42 is d. Here, for example, if L=50 mm, K=100 µm, then S=1000 is
obtained. In this manner, the use of the detection optical system 40 by the optical
lever method enables very highly-sensitive displacement detection to be performed
with a simple configuration.
[0010] FIG. 5 is one example of a scanning type prove microscope 50 by the optical lever
method. Incident light 52 from a laser diode 51 is bent by a mirror 54 arranged immediately
above the cantilever 53 to be applied to a cantilever 53. Reflected light 52a reflected
at the cantilever 53 enters light detection means 55. The light detection means 55
is a quadrant photodiode.
[0011] A sample 56 is fixed on a sample holder 57, and the sample holder 57 is provided
on a fine movement mechanism 58. For the fine movement mechanism 58, a piezoelectric
element (piezo element) is ordinarily used. The fine movement mechanism 58 includes
a fine vertical movement mechanism 59 to adjust a fine vertical movement amount of
the sample 56 and a fine horizontal movement mechanism 60 to scan the sample 56 in
a horizontal plane.
[0012] During the scanning of the sample 56, the fine vertical movement amount z of the
sample 56 is adjusted by the fine vertical movement mechanism 59 so that the deflection
amount θ of the cantilever 53 constantly has a reference value. The fine vertical
movement mechanism 59 is operated by applying a voltage to the piezoelectric element.
From the operation of the fine vertical movement mechanism 59, a surface shape of
the sample 56 can be known. An optical microscope 61 enables the cantilever 53 and
the sample 56 to be observed.
[0013] On the other hand, there is also a scanning type probe microscope having a structure
in which the sample is fixed and the cantilever holding portion is finely moved vertically.
This is used in the case where a large sample such as a semiconductor wafer is observed,
or in the case where a plurality of cantilevers are driven independently. In this
structure, a position of the reflected light on the light detection means is affected
not only by the deflection amount θ of the cantilever but also the fine vertical movement
amount z thereof. Thus, in the measurement output, the effects by the deflection amount
θ and the fine vertical movement amount z of the cantilever are included. Accordingly,
accuracy and reliability of the surface shape of the sample by the output of the fine
vertical movement amount z of the cantilever holding portion has a problem.
[0014] As shown by dashed lines in FIG. 4(c), the cantilever 42 may finely move vertically
(in the fine vertical movement amount z). Although the deflection amount θ of the
cantilever 42 does not change, the reflected light 45a entering the light detection
means 44 moves as shown by reflected light 45c indicated by a dashed line. This movement
is apparently the same as that when the deflection amount θ of the cantilever 42 changes
as shown in FIG. 4(b). Thus, when the reflected light 45a moves on the light detection
means 44, whether this movement is due to the change in the deflection amount θ of
the cantilever 42 or due to the fine vertical movement amount z cannot be distinguished.
[0015] In the case of the dynamic mode, there is a method in which an output signal of the
light detection means 44 is separated into an alternate current signal and a direct
current signal, so that the alternate current signal is used for the control of the
distance between the probe and the sample, and the direct current signal is imaged
as a displacement amount of the fine vertical movement of the cantilever holding portion
41 (e.g.,
JP 2004-69445 A).
This enables an effect by change in relative position between the cantilever holding
portion 41 and the optical system to be eliminated, and since the actual displacement
amount of the cantilever holding portion 41 is imaged, an error of the surface shape
by hysteresis of a fine vertical movement element can be removed.
[0016] However, as in
JP 2004-69445 A, the method for separating the output signal of the light detection means into the
alternate current signal and the direct current signal is effective only in the dynamic
mode, but is not available in the contact mode.
[0017] There is a method in which in order to increase measurement accuracy, a laser optical
system and the light detection means are finely moved vertically in conjunction with
the cantilever to thereby completely compensate for the fine vertical movement of
the cantilever holding portion (Atomic forcemicroscope with improved scan accuracy,
scan speed and optical vision (
REVIEW OF SCIENTIFICINSTRUMENTS, VOLUME 74, NUMBER 10, OCTOBER 2003). However, in this method, a mechanism is very complicated and thus, not general.
SUMMARY OF THE INVENTION
[0018] In the scanning type probe microscope by the method of finely moving the cantilever
vertically, the reflected light on the light detection means is affected not only
by the deflection amount θ of the cantilever but also by the fine vertical movement
amount z thereof. However, conventionally, the effects by the deflection amount θ
and the fine vertical movement amount z have not been able to be separated from the
output of the measurement means. This has resulted in a problem with accuracy and
reliability of the measurement result. An object of the present invention is to provide
a method for separating effects by the deflection amount θ and the fine vertical movement
amount z of a cantilever from measurement output to establish accuracy and reliability
of a measurement result, in a scanning type prove microscope in which a sample is
fixed and the cantilever is finely moved vertically.
[0019] In a scanning type probe microscope of the present invention, a cantilever is cantilevered
by a cantilever holding portion, and the cantilever holding portion is three-dimensionally
driven by a fine vertical movement mechanism and a horizontal scanning mechanism.
Incident light emitted form a laser light source is reflected on an upper surface
of the cantilever, so that reflected light enters light detection means. The incident
light and the reflected light are in a plane not including a long axis of the cantilever.
Since the incident light and the reflected light are in the plane not including the
long axis of the cantilever, movement of the reflected light due to change in a deflection
amount θ of the cantilever and movement of the reflected light due to change in a
fine vertical movement amount z are different in direction on the light detection
means. This enables the change in the deflection amount θ of the cantilever and the
change in the fine vertical movement amount z thereof to be separated from output
of the light detection means.
[0020] The summary of the present invention is as follows:
In a first preferred embodiment, a method for processing output of a scanning type
probe microscope according to the present invention is a method for processing output
of a scanning type probe microscope including a cantilever having a probe at a fore-end
thereof, a laser light source that applies incident light to the cantilever, light
detection means for detecting reflected light by the cantilever, and fine vertical
movement means of the cantilever, wherein the incident light and the reflected light
are in a plane not including a long axis of the cantilever, and the probe is caused
to scan while controlling a fine vertical movement amount of the cantilever by the
fine vertical movement means, the method including decomposing output of the light
detection means into a deflection amount and the fine vertical movement amount of
the cantilever by arithmetic operation.
In a second preferred embodiment of the method for processing the output of the scanning
type probe microscope according to the present invention, assuming that the deflection
amount of the cantilever is θ, and the fine vertical movement amount thereof is z,
a position of the reflected light on the light detection means is (X, Y), and A, B,
C, D are constants specific to the scanning type probe microscope, a relationship
between (X, Y) and (θ, z) is as follows;


from the expressions (1), (2), the following expressions (3), (4) are found;


and
from the position (X, Y) of the reflected light on the light detection means, the
deflection amount θ and the fine vertical movement amount z of the cantilever are
found, using the expressions (3), (4).
In a third preferred embodiment of the method for processing the output of the scanning
type probe microscope according to the present invention, the fine vertical movement
amount z of the cantilever holding portion is changed while maintaining the deflection
amount of the cantilever θ=0 to thereby decide a value of D/B so that a right side
of the expression (3) becomes 0, and the deflection amount θ of the cantilever is
changed while maintaining the fine vertical movement amount of the cantilever holding
portion z=0 to thereby decide a value of A/C so that a right side of the expression
(4) is 0.
In a fourth preferred embodiment of the method for processing the output of the scanning
type probe microscope according to the present invention, the fine vertical movement
amount z of the cantilever is controlled so as to make the deflection amount θ in
the expression (3) constant, and the fine vertical movement amount z obtained from
the expression (4) is imaged.
In a fifth preferred embodiment, a method for processing output of a scanning type
probe microscope according to the present invention is a method for processing output
of a scanning type probe microscope including a cantilever having a probe at a fore-end
thereof, a laser light source that applies incident light to the cantilever, a quadrant
photodiode as light detection means for detecting reflected light by the cantilever,
and fine vertical movement means of the cantilever, wherein the incident light and
the reflected light are in a plane not including a long axis of the cantilever, and
the probe is caused to scan while controlling a fine vertical movement amount of the
cantilever by the fine movement means, the method including matching a border of light-receiving
regions of the quadrant photodiode and a movement direction of the reflected light
by deflection or fine vertical movement of the cantilever, and calculating a deflection
amount θ or a fine vertical movement amount z of the cantilever from output of the
quadrant photodiode.
In a sixth preferred embodiment of a scanning type probe microscope according to the
present invention, a fine vertical movement amount z of a cantilever obtained using
the aforementioned method for processing the output is imaged.
In a seventh preferred embodiment, the scanning type probe microscope according to
the present invention includes the cantilever and light detection means plurally.
EFFECTS OF THE INVENTION
[0021] According to the present invention, there is provided a method for separating the
deflection amount θ and the fine vertical movement amount z of the cantilever from
the output of the measurement means by the simple method in the scanning type probe
microscope that finely moves the cantilever vertically, which establishes the accuracy
and the reliability of the measurement result.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] FIG. 1 is a front view and a side view of a major portion of one embodiment of a
scanning type probe microscope 10 of the present invention. A sample 11 is placed
on a sample table 12. The sample table 12 is an XY stage, which is used to roughly
move the sample 11 when an observation position of the sample 11 is selected. The
sample table 12 is fixed when the sample 11 is measured. A probe 14 at a fore-end
of a cantilever 13 comes into contact with a surface of the sample 11 placed on the
sample table 12. The cantilever 13 is cantilevered by a cantilever holding portion
15. The cantilever holding portion 15 is three- dimensionally driven by a fine vertical
movement mechanism 16 and a horizontal scanning mechanism 17. Incident light 19 emitted
from a laser light source 18 is reflected on an upper surface of the cantilever 13,
and reflected light 19a enters light detection means 20. The incident light 19 and
the reflected light 19a are in a plane not including a long axis of the cantilever
13. If the incident light 19 and the reflected light 19a are in the plane including
the long axis of the cantilever 13, directions of the movements of the reflected light
19a due to change in a deflection amount θ and change in a fine vertical movement
amount z of the cantilever 13 are the same on the light detection means 20. In this
case, the change in the deflection amount θ of the cantilever 13 and the change in
the fine vertical movement amount z thereof cannot be separated from the output of
the light detection means 20. Therefore, the incident light 19 and the reflected light
19a are in the plane not including the long axis of the cantilever 13.
[0023] Since the incident light 19 and the reflected light 19a are in the plane not including
the long axis of the cantilever 13, it is also easy to install an optical microscope
(not shown) immediately above the cantilever 13. Since the installation of the optical
microscope enables the cantilever 13, the probe 14, and the sample 11 to be magnified
and observed, the specifying of scanning position becomes easy.
[0024] In the measurement, a height of the probe 14 is set to a position where a fore-end
of the probe 14 and the sample 11 have no contact with each other, while observing
the sample 11 and the probe 14 with the optical microscope.
The incident light 19 is applied to the upper surface of the cantilever 13 so that
the reflected light 19a is caused to enter the light detection means 20 (e.g., a quadrant
photodiode 20a), and adjustment is made so that the reflected light 19a comes to a
center of the light detection means 20. In other words, when no external force is
applied to the cantilever 13, the reflected light 19a comes to the center of the light
detection means 20. The deflection amount θ of the cantilever 13 at this time is a
reference value (θ=0). In the case where the light detection means 20 is the quadrant
photodiode 20a, outputs of four light-receiving regions are equal when the reflected
light 19a is at the center of the quadrant photodiode 20a.
[0025] That is, when the deflection amount of the cantilever 13 θ=0, and the fine vertical
movement amount of the cantilever holding portion 15 z=0, the reflected light 19a
comes to the center of the light detection means 20 (the quadrant photodiode 20a).
[0026] FIG. 2 is a schematic view of a light-receiving surface of the light detection means
20 (the quadrant photodiode 20a), in which D1 to D4 are the four light-receiving regions.
The center is an origin O, and an X axis and a Y axis, which are orthogonal to each
other, are borders of the respective light-receiving regions D1 to D4. When the deflection
amount of the cantilever 13 θ=0, and the fine vertical movement amount of the cantilever
holding portion 15 z=0, a position of the reflected light 19a is X=0, Y=0. When the
deflection amount θ and the fine vertical movement amount z of the cantilever 13 are
(θ, z), the position of the reflected light 19a of the light-receiving regions D1
to D4 is (X, Y).
[0027] The position (X, Y) of the reflected light 19a is actually obtained as output of
the following electric signals.

[0028] Next, an effect on the movement of the reflected light 19a on the light detection
means 20 (the quadrant photodiode 20a) by an angle formed by the plane to which the
incident light 19 and the reflected light 19a belong, and the long axis of the cantilever
13 will be described.
[0029] When the plane to which the incident light 19 and the reflected light 19a belong,
and the long axis of the cantilever 13 cross at right angles, a θ component corresponding
to the deflection amount and a z component corresponding to the fine vertical movement
amount are orthogonal. When the θ component and the z component are orthogonal, by
appropriately rotating the light detection means 20 (the quadrant photodiode 20a),
the θ component appears on the X axis, and the z component appears on the Y axis as
shown in FIG. 3(a). In this case, the θ component and the z component can be directly
found simultaneously without particularly performing arithmetic operation.
[0030] When the plane to which the incident light 19 and the reflected light 19a belong,
and the long axis of the cantilever 13 cross obliquely, the θ component and the z
component are not orthogonal (they cross obliquely). When the θ component and the
z component cross obliquely, rotating the light detection means 20 (the quadrant photodiode
20a) at an appropriate angle allows the θ component to disappear on the X axis, as
shown in FIG. 3(b). At this time, an X signal may be used as a z signal, and arithmetic
operation is not particularly needed. Moreover, appropriately rotating the light detection
means 20 (the quadrant photodiode 20a) at another angle allows the z component to
disappear on the Y axis, as shown in FIG. 3(c). At this time, a Y signal may be used
as the θ signal, and arithmetic operation is not particularly needed. However, in
the case of the FIG. 3(b) and 3(c), the following arithmetic operation is needed to
simultaneously calculate the θ component and the z component.
[0031] When the deflection amount of the cantilever 13 is θ and the fine vertical movement
amount is z, the position (X, Y) of the reflected light 19a on the quadrant photodiode
20a is approximately expressed as follows:

where A, B, C D are constants decided in accordance with the configuration of the
device (the scanning type probe microscope).
The following expressions (3), (4) are derived from the expressions (1), (2).

Since a right side of the expression (3) is a constant·θ, and a right side of the
expression (4) is a constant·z, calculating left sides of the expressions (3), (4)
from the outputs of X, Y enables the deflection amount θ and the fine vertical movement
amount z to be independently found.
[0032] With the cantilever 13 not vibrated (with the deflection amount θ=0 maintained),
the fine vertical movement amount of the cantilever holding portion 15 is changed
(the fine vertical movement amount z≠0). At this time, a value of D/B is decided so
that an output signal (θ signal) corresponding to the right side of the expression
(3) becomes 0. Next, with the fine vertical movement of the cantilever holding portion
15 stopped (with the fine vertical movement amount z=0 maintained), the cantilever
13 is vibrated (the deflection amount θ#0). At this time, a value of A/C is decided
so that an output signal (z signal) corresponding to the right side of the expression
(4) becomes 0. In the above procedure, although individual values of A, B, C, D are
not known, the value of D/B and the value of A/C can be decided.
[0033] Next, a target value of the deflection amount θ of the cantilever 13 is decided,
and the probe 14 is brought closer to the sample 11 until the θ signal reaches the
value equivalent to this. Corresponding values of the deflection amount θ and the
θ signal are found in advance by thermal vibration noise measurement or the like.
[0034] In this state, the cantilever 13 is horizontally moved to perform the scanning of
the sample 11. The deflection amount θ of the cantilever 13 changes in accordance
with unevenness of the surface of the sample 11, so that the output of the light detection
means 20 (the quadrant photodiode) changes. At this time, the fine vertical movement
amount z of the cantilever holding portion 15 is controlled so as to make the θ signal
constant in the expression (3) (corresponding to the deflection amount θ of the cantilever
13).
[0035] The value of the fine vertical movement amount z of the cantilever holding portion
15 accompanying the above-described control corresponds to the unevenness of the surface
of the sample 11 in a conventional scanning type probe microscope. Actually, since
the fine vertical movement amount z of the cantilever holding portion 15 cannot be
found directly, by conversion from the voltage applied to the piezoelectric element
of the fine vertical movement mechanism 16, the fine vertical movement amount z of
the cantilever holding portion 15 is obtained. That is, by imaging a voltage control
signal inputted to the fine vertical movement mechanism 16, the surface shape of the
sample 11 is obtained. However, it is generally known that the fine vertical movement
mechanism 16 has an error due to nonlinearity, hysteresis and the like, and an obtained
surface shape image contains this error.
[0036] On the other hand, the signal of the fine vertical movement amount z obtained from
the expression (4) by the above-described scanning results from detecting the actual
fine vertical movement amount z of the cantilever 13. By imaging the signal of the
fine vertical movement amount z from this output, a surface shape image can be obtained.
This surface shape image is not affected by the error of the fine vertical movement
mechanism 16. Accordingly, the surface shape image obtained by imaging the signal
of the fine vertical movement amount z obtained from the expression (4) has higher
accuracy than the surface shape image obtained by imaging the voltage control signal
inputted to the fine vertical movement mechanism 16.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037]
FIG. 1 is a front view and a side view of a scanning type probe microscope of the
present invention.
FIG. 2 is a schematic view of a quadrant photodiode as light detection means.
FIGs. 3(a) to 3(c) are schematic views of a θ component and a z component on the light
detection means.
FIGs. 4(a) to 4(c) are schematic views of a conventional detection optical system
by an optical lever method.
FIG. 5 is a schematic view of a conventional scanning type probe microscope.
DESCRIPTION OF THE SYMBOLS
[0038]
- 10
- scanning type probe microscope
- 11
- sample
- 12
- sample table
- 13
- cantilever
- 14
- probe
- 15
- cantilever holding portion
- 16
- fine vertical movement mechanism
- 17
- horizontal scanning mechanism
- 18
- laser light source
- 19
- incident light
- 19a
- reflected light
- 20
- light detection means
- 20a
- quadrant photodiode
- 40
- detection optical system
- 41
- cantilever holding portion
- 42
- cantilever
- 42a
- cantilever
- 43
- laser light source
- 44
- light detection means
- 44a
- light-receiving region
- 45
- incident light
- 45a
- reflected light
- 45b
- reflected light
- 45c
- reflected light
- 50
- scanning type probe microscope
- 51
- laser diode
- 52
- incident light
- 52a
- reflected light
- 53
- cantilever
- 54
- mirror
- 55
- light detection means
- 56
- sample
- 57
- sample holder
- 58
- fine movement mechanism
- 59
- fine vertical movement mechanism
- 60
- fine horizontal movement mechanism
- 61
- optical microscope
1. A method for processing output of a scanning type probe microscope (10) comprising:
a cantilever (13) having a probe (14) at a fore-end thereof;
a laser light source (18) that applies incident light (19) to the cantilever (13);
light detection means (20) for detecting reflected light (19a) by the cantilever (13);
and
fine vertical movement means (16) of the cantilever (13),
wherein the incident light (19) and the reflected light (19a) are in a plane not including
a long axis of the cantilever (13), and
the probe (14) is caused to scan while controlling a fine vertical movement amount
of the cantilever (13) by the fine vertical movement means (16),
the method comprising decomposing output of the light detection means (20) into a
deflection amount and the fine vertical movement amount of the cantilever (13) by
arithmetic operation.
2. The method according to claim 1, wherein assuming that the deflection amount of the
cantilever (13) is θ, and the fine vertical movement amount thereof is z, a position
of the reflected light (19a) on the light detection means (20) is (X, Y), and A, B,
C, D are constants specific to the scanning type probe microscope (10), a relationship
between (X, Y) and (θ, z) is as follows;

from the expressions (1), (2), the following expressions (3), (4) are found;

and
from the position (X, Y) of the reflected light (19a) on the light detection means
(20), the deflection amount θ and the fine vertical movement amount z of the cantilever
(13) are found, using the expressions (3), (4).
3. The method according to claim 2, wherein the fine vertical movement amount z of a
cantilever holding portion (15) is changed while maintaining the deflection amount
of the cantilever (13) θ=0 to thereby decide a value of D/B so that a right side of
the expression (3) becomes 0, and the deflection amount θ of the cantilever (13) is
changed while maintaining the fine vertical movement amount of the cantilever holding
portion (15) z=0 to thereby decide a value of A/C so that a right side of the expression
(4) is 0.
4. The method according to claim 2 or claim 3, wherein the fine vertical movement amount
z of the cantilever (13) is controlled so as to make the deflection amount θ in the
expression (3) constant, and the fine vertical movement amount z obtained from the
expression (4) is imaged.
5. A method for processing output of a scanning type probe microscope (10) comprising:
a cantilever (13) having a probe (14) at a fore-end thereof;
a laser light source (18) that applies incident light (19) to the cantilever (13);
a quadrant photodiode (20a) as light detection means (20) for detecting reflected
light (19a) by the cantilever (13) ; and
fine vertical movement means (16) of the cantilever (13),
wherein the incident light (19) and the reflected light (19a) are in a plane not including
a long axis of the cantilever (13), and
the probe (14) is caused to scan while controlling a fine vertical movement amount
of the cantilever (13) by the fine movement means (16),
the method comprising the steps of:
matching a border of light-receiving regions of the quadrant photodiode (20a) and
a movement direction of the reflected light (19a) by deflection or fine vertical movement
of the cantilever (13); and
calculating a deflection amount θ or a fine vertical movement amount z of the cantilever
(13) from output of the quadrant photodiode (20a).
6. A scanning type probe microscope (10), wherein a fine vertical movement amount z of
a cantilever (13) obtained using the method for processing the output according to
any one of claims 1 to 5 is imaged.
7. The scanning type probe microscope (10) according to claim 6, comprising the cantilever
(13) and light detection means (20) plurally.